Beijing dispatched intelligence-gathering aircraft as well as bombers through international airspace in the East China Sea. The move prompted Japan to scramble fighter jets in response, despite China calling the flyover a “regular” exercise.

The incident occurred on Sunday, when China flew four Chinese H-6 bombers and two intelligence-gathering aircraft through the Miyako Strait between the islands of Okinawa and Miyako and back, the Japan Times reported. Japan scrambled its jets in response, although no violation of Japanese airspace was detected.

The move prompted Japan to ensure it would keep a close watch on the "expanding and increasing" actions of the Chinese military in the area. Beijing, meanwhile, accused Tokyo of blowing the incident out of proportion, stressing that it was part of "regular" drills.

Ren Guoqiant, a spokesman for the Chinese Ministry of National Defense, reiterated that the drills were legitimate. He said his country's military will continue to organize similar exercises in the future, according to Chinese news outlet Sina.

It came just one day after China conducted a similar flyover in the same area, according to a press release from Japan's defense ministry.

Activities around the East China Sea are particularly sensitive for the two sides, which are embroiled in a dispute over the Senkaku Islands, known as the Diaoyu islands in China. The territories, which are 200 nautical miles south of Okinawa, are controlled by Japan.

Chinese military aircraft have routinely been spotted flying over waters near the islands. However, Japan's Defense Ministry said last month that it had scrambled fighter jets a total of 287 times in the first half of fiscal 2017. That number represents a decrease of 120 from the same period in 2016.

Still, the ministry cited a rise in "unusual" flights, including an August drill in the skies above the Kii Peninsula which prompted Japan to express its concern "through diplomatic channels," Defense Minister Itsunori Onodera said at the time.

Although Japan and China are engaged in a dispute in the East China Sea, Beijing is also embroiled in similar feuds with other Asian countries in the South China Sea. Beijing warned Tokyo not to become involved in those disputes in March, threatening a "firm response" if it did so.

Meanwhile, the US is also increasingly flexing its muscles in the region, staging joint drills with Japan and South Korea amid growing tensions with Pyongyang. In September, a pair of Japanese F-15 fighter jets conducted a military exercise with two US B1-B bombers above the East China Sea.

The US military's presence in the region has been slammed by Beijing, with Chinese Foreign Ministry spokesperson Hua Chunying stating in August that a surge in US navy activity represents a danger to the freedom and safety of navigation. "We hope that the United States will pay attention to and properly handle this issue," she said at the time.